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Flow pattern and hydraulic response propagation in selected caves of Moravian Karst
Kůrková, Iva ; Bruthans, Jiří (advisor) ; Knížek, Martin (referee)
This thesis is divided into two parts. The first one is focused on tracer tests carried out in several karst conduits in the Moravian Karst. Several conduits were tracer repeatedly during different discharges. Flow velocity, flow cross section area, longitudinal dispersivity and Peclet number were plotted against discharge for each studied conduit. Based on this comparison of parameters I deduced characteristics of karst conduits for example presence of phreatic channel or vadose channel or multiple channels. I also focused on comparison of my results with publications dealing with the same subject elsewhere in the world. Second part of the thesis is based on measurements of water stage, dischargeand temperature by pressure transducers at inlet and outlet points of karst conduit logged in 10 minutes interval. The goal was to find a relation between the velocity of hydraulic response propagation and discharge. Unfortunately, results show no correlation because there are probably more parameters influencing the velocity such as ratio of vadose/phreatic segments which may change rapidly during flood events.
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Study of vadose zone in northern part of Moravian Karst
Gregorová, Anita ; Bruthans, Jiří (advisor) ; Kamas, Jiří (referee)
This study is focused on the flow through the uppermost part of the unsaturated zone in karstified areas. The information about distribution of transit times and chemical reactions taking place in the unsaturated zone is based on isotopic and chemical composition of cave dripwaters, precipitations and water caught by gravitation lysimeters. The water balance was calculated using measurements of intensity of dripwaters and amounts of water caught by lysimeters and rain gauges. The velocity of a hydraulic shockwave between monitored objects was also estimated according to the delay between significant precipitation event and dripwater intensity increase. The field study took place in the Němcova 1 cave in the northern part of Moravian Karst, near the village Suchdol. It was carried out during the hydrological year 2010/2011. The cave is about 13 m under the surface. The information about composition of overlaying rock above the cave was obtained using geoelectrical and electromagnetic measurements. Studied geological environment is built of 0.5 - 1.5 m of soil, 0.5 - 3.5 m of epikarst and a layer of massive limestone as thick as 10 m. About 70 to 90 % of dripwaters have residence time over 4 years. The distribution of transit time of younger water can be described using the exponencial model (well...
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Hydrology of Amateur cave and sinking streams focused on tracer tests
Gregorová, Anita ; Bruthans, Jiří (advisor) ; Vojtěchová, Anna (referee)
This study briefly summarizes methodology of tracer studies in karst areas (the way how they were carried out and their evaluation). Second part of the study specifies geological, hydrogeological and hydrological situation of the area of interest - northern part of the Moravian Karst, surroundings of Sloup - using available literature on that topic. Description of the area was completed with field measurements done by the author. Their results can be used as a basis for possible future surveys.
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Geochemical, mineralogical and stable isotopes aspects of natural attenuation processes of petroleum hydrocarbons
Topinková, Barbora ; Hrkal, Zbyněk (advisor) ; Holoubek, Ivan (referee) ; Černík, Miroslav (referee)
1 Ústav hydrogeologie, inženýrské geologie a užité geofyziky Přírodovědecké fakulty Univerzity Karlovy Geochemické, mineralogické a izotopické aspekty procesů přirozené atenuace ropných uhlovodíků autoreferát disertační práce Mgr. Barbora Topinková Praha, 2010 2 Lokalita Hněvice leží cca 50 km SZ od Prahy, v blízkosti Roudnice nad Labem. Od r. 1943 se tu nachází velkosklad pohonných hmot, který díky havarijním únikům skladovaných motorových olejů, leteckého benzínu a nafty způsobil ve studovaném území rozsáhlou ekologickou zátěž. Kontaminace lokality má směsný charakter a kromě BTEX je tvořena směsí dalších aromatických uhlovodíků, především trimethylbenzenem a ethyltoluenem. Kontaminační mrak o rozloze cca 0,7 km2 je vázán na kvartérní štěrkopískový kolektor a koncentrace ropných uhlovodíků zde dosahuje až 9 mg/l a 8 800mg/kg. Vzhledem k povaze kontaminantu (LNAPL's) se nejvýznamnější podíl znečištění nachází ve svrchní části kolektoru při hladině podzemní vody a cca 2 m pod ní a směrem k bázi kolektoru klesá koncentrace ropných uhlovodíků až k pozaďovým hodnotám. Zájmová část lokality Hněvice studovaná v rámci této disertační práce a mezinárodního projektu CORONA byla vzhledem k ostatním podobným studiím provedeným na jiných lokalitách ve světě (např. Beminji, Vejen, Banisveld) netypicky umístěna na...
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